Glutathione is a small protein composed of three amino acids - cysteine, glutamic acid, and glycine - that is involved in detoxification and antioxidant mechanisms. Many toxins are dealt with by "handcuffing" the toxin to another molecule so it can be escorted out of the body. The process of adding one molecule to another is called conjugation. Glutathione is one of the most important conjugating compounds in helping the body eliminate fat-soluble toxins such as heavy metals, solvents, and pesticides to transform them into a water-soluble form allowing more efficient excretion via the kidneys.

Health Benefits

The combination of detoxification and free radical protection results in glutathione being one of the most important cancer and aging fighters in our cells. Dietary glutathione intake is associated with protection against some forms of cancer.1,2

The greater the exposure to toxins, the faster the body uses up its supply of glutathione. Without the protection of glutathione, cells die at a faster rate, making people age quicker and putting them at risk for toxin-induced diseases including cancer.

People who smoke, are chronically exposed to toxins, suffer from inflammatory conditions such as rheumatoid arthritis, or suffer from chronic conditions like diabetes, AIDS or cancer typically have lower levels of glutathione. It's a vicious cycle: health problems deplete the supply of glutathione, and reduced levels of glutathione increase the risk of health problems.

In addition to its dietary role in enhancing detoxification and protecting against cancer, studies using intravenous glutathione have found it to be useful in: preventing clot formation during operations,3 reducing the side effects and efficacy of chemotherapy drugs like cisplatin,4,5 Parkinson's disease,6 and increasing sperm counts in men with low sperm counts.7,8 A small study in eight patients with liver cancer showed modest effects when given at a daily dosage of 5,000 mg orally.12 Whether increasing dietary intake with glutathione is effective in these conditions is unknown at this time

Dietary Glutathione is Better than Supplements

Don't look to expensive supplements containing glutathione to boost levels of glutathione in the body. While dietary forms of glutathione appear to be efficiently absorbed into the blood, the same does not appear to be true for glutathione supplements in humans. When healthy subjects were given a single dose of up to 3,000 mg of glutathione researchers found there was no increase in blood glutathione levels.11 The authors of the study concluded "it is not feasible to increase circulating glutathione to a clinically beneficial extent by the oral administrating of a single dose of 3 g of glutathione." In contrast, blood glutathione levels rose nearly 50% in healthy individuals taking 500 mg of vitamin C.12 Vitamin C raises glutathione by helping the body manufacture it. In addition, to vitamin C, dietary sources of glutathione and several other nutritional compounds can help increase glutathione levels including N-acetylcysteine (NAC), alpha-lipoic acid, glutamine, methionine, and whey protein. Also, vitamin B6, riboflavin, and selenium are required in the manufacture of glutathione.

As far as foods go, fresh fruits and vegetables provide excellent levels of glutathione, but cooked foods contained far less.10 Asparagus, avocado, and walnuts are particularly rich dietary sources of glutathione.

Table 1. Comparison of Glutathione in Fresh vs. Cooked Foods
Glutathione amount (dry weight)
(in milligrams per 31/2 oz (100 g) serving)

Food	Uncooked	Cooked
Apples	21	0.0
Carrots	74.6	0.0
Grapefruit	70.6	0.0
Spinach	166	27.1
Tomatoes	169	0.0

For Additional Support in Boosting Glutathione Levels

If you need to really boost your glutathione levels because your liver needs powerful nutritional support due to disease or environmental stress, then I strongly recommend Liver Health from Natural Factors. Basically, this formula provides nutritional and herbal compounds that spare glutathione allowing it to be reserved for more complex reactions. You can liken some of the compounds the liver uses for detoxification such as glucuronate as cheaper currency for detoxification compared to the high price of glutathione. Like glutathione, glucuronate is used by the liver to bind to toxins to help eliminate them from the system. But, it is like a dollar bill and glutathione is like a $100 bill.

Of all the many chemical reactions taking place in the liver cell, the attachment of glucuronate to toxic substances is considered the most important. When glucuronate levels are low, the liver has to use the more expensive currency - glutathione. That currency ultimately depletes the liver's glutathione bank account resulting in significantly impaired detoxification and liver function. By providing glucuronate and other supportive nutrients, the Liver Health Formula reduces the stress on the liver and enhances the liver's ability to detoxify. Clinical studies have shown glucuronate supplementation can improve liver function considerably even in cases of poor liver function due to alcohol abuse, acute and chronic hepatitis, exposure to toxic substances, and diabetes.13,14

For more information on Liver Health, go to http://www.doctormurray.com/articles/pdfs/LiverHealth.pdf

 

Key References:

1. Sen CK. Nutritional biochemistry of cellular glutathione. Nutr Biochem 1997;8:660-72.
2. Flagg EW, Coates RJ, Jones DP, et al. Dietary glutathione intake and the risk of oral and pharyngeal cancer. Am J Epidemiol 1994;139:453-65.
3. Molloy J, Martin JF, Baskerville PA, et al. S-nitrosoglutathione reduces the rate of embolization in humans. Circulation 1998;98(14):1372-5
4. Smyth JF, Bowman A, Perren T, et al. Glutathione reduces the toxicity and improves quality of life of women diagnosed with ovarian cancer treated with cisplatin: results of a double-blind, randomised trial. Ann Oncol 1997;8(6):569-73.
5. Cascinu S, Cordella L, Del Ferro E, et al. Neuroprotective effect of reduced glutathione on cisplatin-based chemotherapy in advanced gastric cancer: a randomized double-blind placebo-controlled trial. J Clin Oncol 1995;13(1):26-32.
6. Sechi G, Deledda MG, Bua G, et al. Reduced intravenous glutathione in the treatment of early Parkinson's disease. Prog Neuropsychopharmacol Biol Psychiatry 1996;20(7):1159-70.
7. Lenzi A, Picardo M, Gandini L, et al. Glutathione treatment of dyspermia: effect on the lipoperoxidation process. Hum Reprod 1994;9(11):2044-50.
8. Lenzi A, Culasso F, Gandini L, et al. Placebo-controlled, double-blind, cross-over trial of glutathione therapy in male infertility. Hum Reprod 1993;8(10):1657-62.
9. Dalhoff K, Ranek L, Mantoni M, Poulsen HE. Glutathione treatment of hepatocellular carcinoma. Liver 1992;12:341-3.
10. Jones DP, Coates RJ, Flagg EW, et al. Glutathione in foods listed in the National Cancer Institutes Health Habits and History Food Frequency Questionnaire. Nutr Cancer 1995;17:57-75.
11. Witschi A, Reddy S, Stofer B, Lauterburg BH. The systemic availability of oral glutathione. Eur J Clin Pharmacol 1992;43(6):667-9.
12. Johnston CJ, Meyer CG, Srilakshmi JC. Vitamin C elevates red blood cell glutathione in healthy adults. Am J Clin Nutr 58:103-5, 1993.
13. Miglio F, et al. Efficacy and safety of oral betaine glucuronate in non-alcoholic steatohepatitis. Arzneim Forsch 2000;8:722-7.
14. Miglio F, et al. Efficacy of glucuronates versus placebo in chronic hepatitis: A randomized, double-blind study. Advances Therapy 1995;12:299-312.

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Michael T. Murray, N.D., is widely regarded as one of world's leading authorities on natural medicine. A prolific author, Dr. Murray has written over 20 books on health and nutrition including the best-selling Encyclopedia of Natural Medicine and his latest book The Encyclopedia of Healing Foods. Dr. Murray is also Director of Product Development and Education for Natural Factors one of the leading manufacturers of natural products.